Even our pets are fat …
I took a sneak peak at our much loved and seriously plump puss some years ago when I read ‘even our pets are fat’ in the first chapter of Prof Jennie Brand-Miller’s original manuscript for The Low GI Diet. Today our much loved Silkie is a rather streamlined 6kg. We fed him less and played with him more – he particularly likes pelting a ping pong ball back at you. It wasn’t easy. It wasn’t speedy. And we had to harden our hearts to much pathetic yowling in front of cupboard and fridge doors. But now he really does seem to ‘eat to appetite’. Mostly ...

Worldwide, as our waistlines have expanded, so have those of our pet animals (and animals in zoos). In the US, the sixth annual National Pet Obesity Awareness Day Survey conducted by the Association for Pet Obesity Prevention (APOP) in 2012 found 52% of dogs and 58% of cats to be overweight or obese. That equals approximately 80 million US dogs and cats at increased risk for weight-related disorders such as diabetes, osteoarthritis, hypertension and many cancers. It’s generally considered that we pet owners are the problem and in the wild animals are lean. But it’s a bit more complicated than just calories in/calories out as Dr Barbara Natterson-Horowitz reports in her new book, Zoobiquity.

Evolving Health blogger David Despain has had a long-held fascination with the topic of how health in the animal world relates to the human world. He recently chatted with Dr Barbara Natterson-Horowitz and we reproduce an excerpt of that interview here with his kind permission.

David Despain: Being a nutritionist, one of my favorite chapters in your book was ‘Fat Planet’ where you tell the story of two obese Alaskan grizzlies Jim and Axhi who were treated at Chicago's Brookfield Zoo by nutritionist Jennifer Watts. Watts changed their diet and lifestyle in ways that was informed by knowledge of their natural ecology. It wasn’t a ‘perfect wild diet’ – as that’s fantasy – but there were changes like considering the environment’s cyclical periods of abundance and scarcity as well as season’s effect on their intestinal microbiomes. Previously, I’ve written about nutritionists doing similar things both with lemurs that suffer from obesity and diabetes. What would you say are the key takeaways in dietary advice that humans can learn from your examples?

Dr Barbara Natterson-Horowitz: There were so many surprises that we encountered in researching the book. One early misconception that we bumped up against was this idea that only human beings overeat. There seems to be this fantasy that animals in their natural setting have internal regulatory systems that would result in eating only to satiety and that would be it. This idea was so wrong. We now understand that, actually from an evolutionary perspective, animals that are likely to encounter periods of scarcity do [overeat] when they encounter periods of abundance ... [then] they absolutely over-consume and sometimes spectacularly over-consume. That was already the beginning of a set of really surprising findings. If there’s abundance and there's no predatory threat, they’ll just consume and consume.

The other real biggie was that … it’s pretty much been assumed until very recently that it was all about calories in, calories out. I think most physicians have had patients that say they are not losing weight, and they swear to you that they’re eating 900 calories a day – do you really think that that’s true? I think most physicians would be skeptical and think that their patients are probably not telling the truth or not aware of how much they’re eating.

So, one of the exciting and surprising aspects of researching this chapter was to learn about all of these other factors that go beyond calories in and calories out. These could very well be influencing metabolism in both individual human patients and other species as well – things like the seasonal microbiome, and circadian variation, even climate change, endocrine-modifying chemicals, and perhaps antibiotics in the environment. These are really interesting ideas to think about even in [the context of] the obesity epidemic as not being isolated to human beings, but perhaps being more species-spanning.’

– In Zoobiquity: The Astonishing Connection Between Human and Animal Health, you'll learn all sorts of interesting facts: that dinosaurs also suffered from cancer, that fish faint, that horses suffer from sexual dysfunction, that all sorts of wild animals can at times develop eating disorders or overeat and become obese, that koalas suffer from chlamydia, that birds self-injure, and that wallabies get stoned. The term ‘zoobiquity’ was coined by UCLA cardiology Professor Barbara Natterson-Horowitz, MD, and science journalist Kathryn Bowers to describe their call for a coming together of three scientific fields: human medicine, veterinary medicine, and evolutionary biology. It's available from good bookshops and online.